The New York Times has announced that, with the exception of some articles in the 1923 to 1986 period, online access to its site will be free starting at midnight tonight. Free backfiles will be available for the 1851 to 1922 and 1987 to present periods.
Here's an excerpt from "Times to Stop Charging for Parts of Its Web Site":
What changed, The Times said, was that many more readers started coming to the site from search engines and links on other sites instead of coming directly to NYTimes.com. These indirect readers, unable to get access to articles behind the pay wall and less likely to pay subscription fees than the more loyal direct users, were seen as opportunities for more page views and increased advertising revenue. . . .
Colby Atwood, president of Borrell Associates, a media research firm, said that there have always been reasons to question the pay model for news sites, and that doubts have grown along with Web traffic and online ad revenue.
“The business model for advertising revenue, versus subscriber revenue, is so much more attractive,” he said. “The hybrid model has some potential, but in the long run, the advertising side will dominate.”
Source: Pérez-Peña, Richard. "Times to Stop Charging for Parts of Its Web Site." The New York Times, 18 September 2007, C2.